Stopper for acid bottles and process for making the same



March 6, 1928.

' D. ESTES STOPPER FOR ACID BOTTLES AND PROCESS FOR MAKING THE SAME Filed Jan. 24. 1925 FD? 0621i??? Dana Fates Patented Mar. 6, 1928.

A v 1,661,416- "UNITED STATES PATENT OFFICE.

DANA ESTES, OF BROOKLINE, MASSACHUSETTS.

'srorrnn ron ion) BOTTLES Aim rnoonss non MAKING THE SAME.

Application filed January This invention relates to improvements in sto pers for acid bottles and processes for that an accidental fracture ofthe porcelain isfnot likely to interfere with the proper function of the stopper when the apparatus is put to use.

In'extinguishers of this type a canister ordinarily holding several gallons of alkali solution has in its top portion a bottle of acid, usually sulfuric, whose stopper is loosely seatedand is arranged in harmony with adjacent parts so as to keep the acid and its creepage safely away from met-aland alkali; but so that upon inversion of the acid container the stop er will fall to a position which permits out ow'of acid'from the then inverted bottle, and which to an extent regulates or controls the rate of flow. Such stop pers are usually made of porcelain, which is a brittle material liable to fracture; andalthough lead has been sometimes used it and other metals are objectionable as being liable to corrosion if acid gets at them. It is i the purpose of the presentinvention to provide so that the stopperfragments will be 5 held together ifa fracture occurs, and not fall apart and lodge in such a way as totin- \terfere with the outflow of acid when the fire extinguisher is wantedfor use; t It has been proposed be me in a co-pending application for patent Serial 605,384, dealing more especially with the material steatite for manufacture of stoppers, of which this present application is in part a division, that a preventative against the separation offragmentsmay be had by providing a'metallic core with which the earthy 7 material of the stopper is enmeshed by structural shapes such as screw threads or flanges on the metallic element. The present invention provides an improvement upon that, available inthe case of porcelain, permitting one to dispense with. the screw threads or the flanges and to employ a piece ofwire which is initially smooth. This core v is held in place with respect to the porcelain in which it is embeddedby a species of flux 24, 1925. Serial No. 4,534.

therewith and resulting adsorption or microengagement. For this purpose nichrome wire may be used advantageously, having a coefficient of expansion which does not differ materially from that of the stopper.

When such acore is inserted in the stopper during the molding of the clay, and the clay is then fired in a kiln in theusual manner, 7

the metal body of the wire itself, but the exact details of this structure are extremely difficult-to determine because of the microscopic nature of-the dimensions involved.

'It'is an advantageous result of theinvention that a stopper can-be made for the purposes stated in which th'ereis reinforcement by metal andyet no metal whatever is exposed to the acid; and in a preferred form indeed no metal need be exposed at all. A

which is to becomeporcelain, with the porcelain at theinner end of the stopper covering deeply that end of the reinforcingrod. The other end of the rod is at the surface of the clay; but the glaze of theporcelain which is next applied covers itwith a. thin coat through which the end ofthe rod isvisible. It isintended that the patent shall cover, by suitable expression in the appended claims, whatever features of patentable novelty exist'in the invention disclosed.

In'the accompanying drawings: Figure 1 represents a medial section through the end portion of a portable fire extinguisher, while inverted as'for use; and Figure 2 is a medial vertical section through the lower tip end of the stopper which is seen in Figure 1, greatly enlarged. Practice of the invention is very simple. A body of clay suitable for making porcelain when fired is prepared with a piece of suitable wire arranged axially within it, the said clay being molded into the form of a stopper and the said wvire being here shown in the form of a straight rod inserted endwise, in close contact with the clay. Preferably this wire doesfnot extend so far as to become exposed at the inner end of the axis, toward the acid. It may, however, remain exposed at the other end,'which is simple length of wire rod is set in the clay ti U the to a of the stopper when the apparatus is upright awaiting use, being the under part of the stopper as represented in Figure 1. If any projects after the burning it may be ground down till flush with the porcelain; and the later application and firing of the glaze makes a coating over the exposed end as seen clearly in the under part of Figure 2. The rod may be ordinary nichrome wire, which, I understand to be alloy having a high percentage of nickel alloyed with steel, to which there may be added other matter as chromium which will increase the refractory power and the resistance to chemical action, although I have not found this necessary. The wire .may be, for example, from 35 to 45 one thousandths of an inch in diam eter, clean and bright; and theformula for its composition may be so selected that the wire will have approximately the same coeflicient of expansion as the clay or porcelain, so that during the cooling it does not break free from its engagement.

In the process of manufacture the clay is selected, mixed andotherwise treatedor prepared as heretofore for the manufacture of the article and then is formed into the desired shape by the usual molding process. It is well understood that articles such as these stoppers are molded by pressure upon a body of clay between a pair of suitably shaped dies. The rod that is to bein the core of the finished stopper of the invention may be slightly longer than is portrayed at 12 in Figure 1, having its lower end, extending below the lower surface of the stopper as there seen and set into a suitable socket formed in the matrix, which thus holds the rod upright in the midst of the space which is to be filled with clay. The clay is then packed into the matrix around this rod, the top part of the die is closed over it, and the contents molded by strong pressure as usual. Being then removed and burned in a kiln as usual, the clay becomes porcelain, and a physico-chemical reaction occurs between the metal of the rod and the ingredients of the clay, as is manifest by the discoloration of' porcelain and of the surface of the rod; and by the appearance of a film 16, having the nature or general aspect of a metallic oxide, between the rod 12 and the main body 10 of porcelain. On a specimen of the preferred type there appears to have been, as a result of the burning and cooling, some degree of interfiux with the vitreous adjacent matter, and an adsorption upon the metallic surface. After higher temperature these effects are more marked and they are less at lower; but in either case the result is that the straight smooth wire rod has become securely engaged and held within the porcelain mass. A portion of the rod projects a little from the porcelain. being that portion which was set into the matrix; and this can be cut off with nippers and then ground .down till it is flush with the surface of the porcelain. Then the application of glaze and its subsequent burning will cover the end of the rod together with the porcelain as shown by the hard glaze 14 at the lower part of Figure 2, covering the end of the rod. It is to be observed, however, that no particular defect in the finished article would be recognized even though the glaze did not cover the outer end of the .rod.

Figure 2 shows on a greatly enlarged scale, more or less diagrammatically, the porcelain 10, the nichrome wire 12, and the interveningengaging film 16 which the .wire rod is believed to have adsorbed on its surface, the intcrtlux being indicated by the irregular line forming the boundary between the part 16 and porcelain 10. It is important to regulate the flow of the fire extinguishing fluid through the discharge :20, as is already well known. If a finished stopper becomes broken the central rod will hold in place any parts which encircle the rod. And if in some places it should happen that the interilnx has not been perfect as above described so that at those placesthe fragmcntis loose upon the rod, nevertheless the holdingof. the rod at the other places willhold the loose piece in place and thus will maintain the predetermined size of opening for exit of the acid to mix with alkali, seen in Figure 1 at 18.

I claim as my invention:

1. The combination, withan inycrtihle fire extinguisher having an acid bottlc,ofa loose stopper for the bottle, subject to concussion within the extinguisher when thecxtinguisher is inverted and means to maintain the material thereof in stopper formation notwithstanding its fracture; said stoppercomprising a body of vitrified earthy material; and said means comprising a rod, made of metal whose coefiicient of expansion close to that of said earthy material, penetrating said material and arranged in intimateclinging contact therewith, whereby fracture of the stopper is resisted, and therev is a tendency of the fragments, iffracture occurs, to be held in the stopper formation by the said rod.

2. The combination, with an invertible tire extinguisher having an acid bottle, of a loose stopper for the bottle subject to concussion within the extinguisher when the extinguisher is inverted, and means to maintain the material thereof in stopper formation notwithstanding its fracture; said stopper comprising a body of porcelain; andsaid means comprising a rod made of metal whose coetiicient of expansion is substantially the same as that of the porcelain, pcnct'ating said porcelain; there being an interflux between the porcelain and said rod whereby fracture of the stopper. is resisted, and there till III)

intimate and clinging contact with the sur: face of said-rod, whereby fragments of a 10 fractured stopper cling to the rod andby it are held together. I

' Signed at Boston, Massachusetts, this twenty-second day of January, 1925.

DANA ESTES. 

